A former head of fraud at Lloyds Banking Group has herself been charged with a £2.5m fraud, causing blushes at the part-nationalised bank.

Jessica Harper, 50, is accused of submitting false invoices to the tune of £2.46m when working as head of fraud and security for digital banking. It is thought her work involved managing supplies and that the invoices did not relate to personal expenses.

The fraud is alleged to have started in September 2008, shortly before Lloyds had to be bailed out by the taxpayer. The UK government owns 41% of Lloyds after funnelling £20bn of rescue funds into the bank during the financial crisis.

Harper, who lives in Croydon, south London, will appear before Westminster magistrates court next Thursday, charged with one count of fraud by abuse of position.

Andrew Penhale, deputy dead of the CPS central fraud group, said: "The charge relates to an allegation that between 1 September 2008 and 21 December 2011 Jessica Harper dishonestly and with the intention of making a gain for herself abused her position as an employee of Lloyds Banking Group, in which she was expected to safeguard the financial interests of Lloyds Banking Group, by submitting false invoices to claim payments totalling £2,463,750.88, to which she was not entitled."

He said the CPS had decided there was "a realistic prospect of conviction and a prosecution is in the public interest".

Lloyds said: "As the court process is ongoing it would be inappropriate for us to comment."